This invention relates generally to leak detectors and methods thereof and more specifically to a leak test device and method of use for leak testing seams in an article in which only the seam is subjected to a pressure differential.
In the art of leak testing, it is often necessary to leak test an enclosure or joint of an unassembled fluid system in which it is impossible to pressurize or evacuate the enclosure or joint to effect a comprehensive leak test. A conventional prior art helium leak test, for example, requires a sealed section or container to be evacuated to a pressure of less than 0.5 torr. A helium leak detector is connected in the purge pump line and helium is introduced on the side of the sealed section or container away from the evacuated section or container. The presence of helium in the leak detector indicates a leak into the evacuated volume. The problem encountered in certain fragile or low pressure containers is that the pressure differential required for leak testing joints or seals in the container, for example, may collapse the container.
Another problem encountered in the production of even pressurized systems is testing of joints of partially assembled portions. In a piping system, for example, a seal weld or other joint of a component pipe section may require leak testing in a fabrication shop before final assembly. With prior leak test techniques the component section must be plugged or otherwise sealed to evacuate or pressurize the pipe section.
Thus, there is a need for a test fixture and method to leak test seams, such as container seals or pipe joints which does not require the application of a pressure differential to the entire surface area of the container or joined sections.